Equivalent & Substitute Parts for 5KP78-B TVS Diode

Part Overview

The 5KP78-B is a unidirectional Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose transient protection applications. This component features a 78V reverse standoff voltage rating and 5000W peak pulse power handling capability in a P600 axial through-hole package. The 5KP78-B is classified as obsolete, necessitating identification of active equivalent alternatives that maintain electrical and mechanical compatibility for new designs and production continuity.

Substiute Parts

5KP78-B

Littelfuse Inc.In Stock: 8205KP78-B Datasheet

Current PartRFQ

5KP78A

Littelfuse Inc.In Stock: 42885KP78A Datasheet

DirectRFQ

5KP78A-B

Littelfuse Inc.In Stock: 8895KP78A-B Datasheet

DirectRFQ

5KP78E3/TR13

Microchip TechnologyIn Stock: 11305KP78E3/TR13 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 5KP78-B is determined by strict equivalence across the following critical parameters:

• Voltage - Reverse Standoff (Typ): Must be 78V to maintain circuit protection threshold
• Unidirectional Channels: Must be 1 (single channel configuration)
• Power - Peak Pulse: Must be 5000W (5kW) for equivalent transient energy dissipation
• Mounting Type: Must be Through Hole to ensure PCB compatibility
• Package / Case: Must be P600, Axial for mechanical fit and lead spacing
• Operating Temperature Range: Must support -55°C ~ 175°C (TJ) for thermal compatibility
• Type: Must be Zener diode for consistent protection characteristics

The identified substitute parts meet these core electrical and mechanical requirements while offering active product status and improved availability compared to the obsolete 5KP78-B.

Parameter Comparison

Engineering Selection Recommendations

5KP78A (Littelfuse Inc., Active Status)

The 5KP78A is a direct Littelfuse equivalent with active product status and high inventory availability (4200 pcs). It maintains identical reverse standoff voltage (78V), power rating (5000W), and thermal operating range. The clamping voltage is 126V compared to 132.3V in the 5KP78-B, representing a 4.8% reduction. This part is supplied in Cut Tape (CT) packaging and carries ROHS3 compliance with REACH Affected status.

5KP78A-B (Littelfuse Inc., Active Status)

The 5KP78A-B is functionally equivalent to the 5KP78A with identical electrical specifications. It differs in packaging format (Bulk) and REACH status (REACH Unaffected). This variant offers 824 pcs inventory availability and is suitable for applications where bulk packaging is preferred or REACH compliance requirements differ from the CT variant.

5KP78E3/TR13 (Microchip Technology, Active Status, MFR Recommended)

The 5KP78E3/TR13 is the manufacturer-recommended alternative from Microchip Technology, supplied in Tape & Reel (TR) format with 1063 pcs inventory. It maintains the 78V reverse standoff voltage and 5000W power rating. The clamping voltage is 139V, representing a 5.1% increase relative to the 5KP78-B. This part carries ROHS3 compliance with REACH Unaffected status and is designated as the primary cross-manufacturer substitute.

All three substitute parts satisfy the core electrical and mechanical requirements for direct replacement in applications currently using the 5KP78-B.

Frequently Asked Questions (FAQ)

Q: Can the 5KP78A be used as a direct replacement for the 5KP78-B?

A: Yes. Both parts share identical reverse standoff voltage (78V), power rating (5000W), operating temperature range (-55°C to 175°C), and P600 axial through-hole package. The 5KP78A is active and widely available, making it the primary Littelfuse substitute.

Q: What is the significance of the clamping voltage difference between 5KP78-B (132.3V) and 5KP78A (126V)?

A: The clamping voltage represents the maximum voltage across the diode during transient suppression at peak pulse current. The 5KP78A's lower clamping voltage (126V vs 132.3V) provides slightly more aggressive transient suppression. Both values fall within the acceptable range for 78V standoff applications and do not affect substitutability.

Q: Why is the 5KP78E3/TR13 designated as manufacturer-recommended?

A: The 5KP78E3/TR13 is explicitly identified as the MFR (manufacturer) recommended substitute in the component database. It is supplied by Microchip Technology in active status with Tape & Reel packaging suitable for automated assembly. This designation indicates cross-manufacturer compatibility validation.

Q: Does packaging format (Cut Tape vs Bulk vs Tape & Reel) affect electrical compatibility?

A: No. Packaging format affects only supply chain logistics and assembly automation compatibility. The electrical and mechanical specifications remain identical across all packaging variants. Selection should be based on procurement requirements and assembly equipment capabilities.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. The 5KP78-B and all identified substitutes (5KP78A, 5KP78A-B, 5KP78E3/TR13) carry ROHS3 Compliant certification, ensuring regulatory compliance for restricted substance content.

Q: What is the difference between REACH Affected and REACH Unaffected status?

A: REACH Affected indicates the part may contain substances subject to REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) regulations. REACH Unaffected indicates the part does not contain such substances. Selection depends on end-market regulatory requirements. Both statuses are acceptable for general industrial applications.